Not Applicable
Not Applicable
On Feb. 14, 2002, the Federal Communications Commission (FCC) issued a First Report and Order for UWB (ultra-wide band) technology, which authorized the commercial deployment of UWB technology. A spectrum mask was released to ensure that UWB signals will not interfere with sensitive devices such as GPS (global positioning) systems. In the spectrum mask, there is a huge continuous bandwidth where the EIRP emission level (in dBm/MHz) is constant from 3.1 GHz to 10.6 GHz that is attractive for UWB communication applications.
Before the introduction of the mask, much of the UWB signaling techniques utilized nanosecond Gaussian pulses which occupy a frequency spectrum from DC to a few GHz. However, with the introduction of the mask by the FCC, most of these systems require modification. Generating nanosecond Gaussian pulses and achieving optimum correlation detection were readily achieved with a very simple system before the FCC ruling. However, after the ruling, useful systems require generating the nanosecond pulses within 3.1 GHz to 10.6 GHz range while at the same time achieving optimum correlation detection. It is not straightforward to convert systems before the ruling to both fit into the current FCC mask and at the same time to achieve optimum correlation detection.
A circuit to generate antipodal PSK signals and a correlator circuit for recovering information from PSK (phase shift keying) UWB transmissions includes providing a circuit component characterized by a transfer function having alternating stable and unstable regions. By setting the operating point in a stable region or an unstable region, a non-oscillatory or an oscillatory output signal can be produced. At the transmitter, in-phase sinewaves are generated by moving operating point from stable region 1 to an unstable region and an out-of-phase sinewave is generated by moving the operating point from stable region 2 to unstable region. This method of generating transmitted signal is used at the receiver to correlate the transmitted signal to achieve optimum detection.